Method and device for manufacturing helically seamed tube

ABSTRACT

A helically seamed tube is produced from a strip-shaped profiled blank by turning the profiled blank by a revolving rolling device to the extent of one lead of the helical seam and bringing the profiled blanks which will form the seam into seaming contact with each other. At least three rolling devices are in contact with the helical seam and finish the seam while supporting the tube.

United States Patent [72] inventors Eino Kale rvo Mnlkki 3,247,692 4/1966 Davis 72/49 Etel l'lesperiankatu 18 A; 2,136,942 11/1938 Freeze... 72/50 Valentin Silde, 3 linja23 B, both of 2,595,747 5/1952 Anderson 72/50 Helsinki, Finland 1,739,774 l2/l929 Thorsby 72/49 [211 App]. No. 691,642 3,192,754 7/1965 Kehne et a1 72/49 1221 1:2 FOREIGN PATENTS [45] Patented July 1 [32] Priority D. 2" 1966 4,513 2/1894 Great Britain................ 72/50 [33] Finland Primary Examiner-Richard .l Herbst l3 1 1 3404/66 Attorney-Richards & Geier [54] METHOD AND DEVICE FOR MANUFACTURING HELICALLY SEAMED TUBE 1 Claim, 6 Drawing Figs.

[52] Us. Cl 72/49 ABSTRACT: A helicany seamed tube is produced f a 1511 3"/12 strip-shaped profiled blank by turning the profiled blank by a [50] Field 0! Sql'dl 72/49, '50 revolving rolling device to the extent f one lead of the helical seam and bringing the profi1ed blanks which will form the [56] References Clad seam into seaming contact with each other. At least three UNITED STATES PATENTS rolling devices are in contact with the helical seam and finish 3,417,587 12/ 1968 Campbell 72/49 the seam while supporting the tube.

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SHEET 1 OF 3 Fig.3 INVENTORS:

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ATTOILNESLS PATENTED JUL27 1971 SHEET 2 OF 3 Fig.5

INV E NTO RSZ EJCMCLZKKLLA MSLZC/(f ATTDILNEEJS METHOD AND DEVICE FOR MANUFACTURING IIELICALLY SEAMED TUBE The present invention relates to a method and device for producing helically seamed tube from a strip-shaped profiled blank.

Nowadays several different methods are known for manufacturing helically seamed tubes from metal strip which prior to its introduction in the seaming device proper has been shaped to have such a suitable profile which enables the ultimate seam to be made and shaped. Of course, the preprofiling of the metal strip may then take place in the machine itself which performs the seaming, or it may be accomplished separately. The commonest shortcoming of previously known methods and devices has been that they usually include devices which one has been compelled to exchange when starting to produce a tube of different diameter or to use strip of another width.

The objects of the present invention include elimination of these drawbacks and achievement of such a method and device that one and the same machine can be used without exchangeable tools, merely by performing certain adjustments, to manufacture tubes of even considerably different diameters and even to manufacture conical tube sections by means of which tubes of different diameters may be connected to each other.

One of the present inventions most essential advantages is the simplicity of the devices required in it, and the fact that one is enabled to change the production of the seaming machine very rapidly from one type of tube to another, all of which results in considerable reduction of the production costs.

The invention is described in greater detail in the following, with reference to the attached drawing and to the different embodiments of the invention illustrated by it, partly in the way of sketches.

FIG. I shows a device for use according to the invention, seen from one side. i

FIG. 2 shows the same device, seen from above.

FIG. 3 shows, in the form of profile diagrams, the different phases of forming the helical seam.

FIG. 4 shows some other profile shapes of the helical seam which can be produced by means of the invention.

FIG. 5 is an enlarged presentation of part of FIG. 1.

FIG. 6 shows, from the side as in FIG. 1, another embodiment of the device used according to the invention.

The metal strip 1 enters the machine, drawn by the rolls 3. At the same time the rolls 3 shape the strip blank 1 to have the desired profile so that a profiled strip 2 is produced, which is fed onwards in the device. The strip 2 then passes through an arc of 360, forming a length of the tube corresponding to one lead of the helical or screw line formed by the helical seam, and arrives at the rolling device 4, which initiates the finishing of the helical seam. On the length of the next lead of the screw line, starting at the rolling device 4, two further rolling devices 5 and 6 have been placed, which finish the helical seam. It is favorable in view of the seaming work quality as well as the reliable operation of the entire device if all the rolls participating in the seaming operation are driven, that is if they draw the tube which is being formed in the direction of the helical seam with the same speed. If preprofiled strip is used in the device, the rolls 3 are obviously unnecessary and may be replaced with some appropriate preprofiled strip feeding device, in which case the feed has to be synchronized with the traction of the rolls producing the helical seam.

If the width of the strip 2 is changed but the outer diameter of the tube 9 to be produced remains unchanged, the mutual position of the rolling devices is adjusted in the longitudinal direction of the tube which is being formed, as required. If it is desired to change the outer diameter of the tube produced by the device, the rolling devices 5 and 6 are displaced in their guides 8. In the embodiment accordin to FIG. 1, oblong openings in the end plate 7 act as guides In the embodiment shown in FIG. 6 the rolling devices 5 and 6 have been mounted on slides 10, both slides moving along two guide bars, and by turning the spindle 12, which acts on screw spindles 11 interacting with the slides 10, the slides 10 and the rolling devices 5 and 6 along with them may be positioned as desired. The spindle 12 (FIG. 6) may also be arranged, e.g. by means of the appropriate gear ratio and transmission, to per form a reciprocal rotation so that one may then with the device produce a helically seamed tube the diameter of which alternately decreases and'increases. In order that the rolling devices according to FIG. 6 might be made to be driven rolls and to exercise traction, the power is most suitably transferred to the slides by means of chain transmission and further carried by bevel gears to the. rolling devices proper (5 and 6), which in the embodiment according to FIG. 6 both include two rolls rotating in opposite directions and pressing the helical seam between them.

In FIG. 3 the three different phases a, b and c occurring in the manufacturing of one type of helical seam are shown. These profile shapes of the seam are produced in the device at the pints indicated by the same reference symbols in FIG. 3. In FIG. 4 some other such helical seam profiles are presented which can be produced with a device and method according to the'invention.

A device according to the invention can naturally be provided with more than three rolling devices, but there is no reason for this as a rule. The device would merely become unnecessarily complicated, and achievement of certain adjustments would be rendered more difficult. It is also possible to install in the device various supporting and bracing elements, such as rolls, especially when manufacturing of large-diameter tubes is concerned, but such rolls are obviously in no wise connected with the producing of the helical seam itself, that is, they do not actually fall within the sphere of the invention.

It is possible at the same time, e.g. when tubes consisting of very thin material are seamed, to place within the tube at the points where seaming is in process, a bracing roll or some equivalent organ, against which theseaming is done.

With a prototype of the device according to the invention, in which three rolling devices have been used distributed over the length of one lead of the helical seam produced, with mutual phase shift, tubes have been seamed with diameters varying from the order of 1 cm. up to 1.5 meters. It is easy in actual practice to achieve even larger diameters if need exists.

In the foregoing the invention has been described in the first place with reference to the embodiments shown in the drawing. However, the invention is not restricted to them and it may vary within the scope defined by the attached claims.

We claim:

1. A device devoid of mandrel for making rigid helically seamed tubing, said device comprising a device for profiling and feeding a metal strip, at least three rolling devices, means rotating one of said rolling devices in synchronism with the speed of said feeding device, said one rolling device engaging and turning the metal strip to the extent of 360 and bringing its edges into seaming contact with each other, the other two rolling devices being spaced from the first-mentioned rolling device to the extent of a pitch of the helical seam and engaging the rolled strip to join its helically extending seams, two guides extending at an acute angle to each other and carrying said two other rolling devices which are movable upon said guides and screw spindles carried by said guides and engaging said two other rolling devices and geared to a common shaft for simultaneously varying their distances from the first-mentioned rolling device while the device is in operation. 

1. A device devoid of mandrel for making rigid helically seamed tubing, said device comprising a device for profiling aNd feeding a metal strip, at least three rolling devices, means rotating one of said rolling devices in synchronism with the speed of said feeding device, said one rolling device engaging and turning the metal strip to the extent of 360* and bringing its edges into seaming contact with each other, the other two rolling devices being spaced from the first-mentioned rolling device to the extent of a pitch of the helical seam and engaging the rolled strip to join its helically extending seams, two guides extending at an acute angle to each other and carrying said two other rolling devices which are movable upon said guides and screw spindles carried by said guides and engaging said two other rolling devices and geared to a common shaft for simultaneously varying their distances from the first-mentioned rolling device while the device is in operation. 